I just upgraded my FireboxV from 11.12.4 to 12.1.1 and I can't talk to it on any interface. The console still works though. Help!
The order of interfaces has probably changed - FireboxV now orders the interface by MAC address instead of "the order in which they start up", which was sometimes unreliable.
for more, see https://watchguardsupport.secure.force.com/publicKB?type=KBKnownIssues&SFDCID=kA42A000000HAmVSAW&lang=en_US